Audio Research ls 16 vs. Audio research ls 16II

I'm in the upgrade mode. Is it worth the $1000 to upgrade to the AR ls16II or sell/trade and go in another direction.
My amp is the McCormick dna1 revA, speakers are vandersteen 3a sigs and cd is cary 308. HELP.
I find that upgrading at the factory is not as cost effective as buying the product in the used market. I've owned the LS16-MKII and it was sweet. I ran it into my Martin Logans via a VT100-MKIII Amp.

No complaints with this pre-amp. Just keep in mind it can be had in the used market for less than 2K before you spend a lot of money upgrading.
I would first consider looking into a Great Northern Sound modification by Steve Huntley. His results with ARC preamps are highly praised. His advice regarding various ARC models is valuable and unbiased. Search Great Northern Sound on Audiogon for others experience.
I'll second Steve Huntley

also for the price of the lateral move to an ls 16 you could move up to something grand like the ls 5
a whole different and more musical animal

do a search on them here

Run the other way. Seriously, put some nice amperex 6dj8's in the lS-16. Have a service tech re-set the bias. You may find that you already have your last pre-amp.
You should sell the LS16 to me and buy something new.